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Nag1 overfilled transmission(fluid/filter change)

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Old May 17, 2023 | 08:57 PM
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Unhappy Nag1 overfilled transmission(fluid/filter change)

I took out about 3.5qs, normally people get about 4; i then added 3.5qs. Well after driving awhile and getting the trans to 160f plus, i checked the dipstick and it read low. So i added a little less than a half quart. I then drove around and all seemed fine and dandy. I then went to check it, and it read really high on one side, and then just at the top of where HOT should be. Im going to let it cool down and remove what i added. I hate the dipstick so freakin much, so hard to read. Is it really bad that i overfilled by a half quart? It for sure read low the first time, thats why im so pissed. I know its better to be low than high, so ill take out a half quart in the morning. Nothing seeped out of the pan or blew out the breather tube. Im just confused because it read under the cold low dot when cold, and then under the low hot when hot, then when i filled her with some more, it read way high!

Last edited by JeepLiam; May 17, 2023 at 09:35 PM.
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Old May 18, 2023 | 06:54 AM
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I agree, that dipstick is difficult to read, not to mention when adding anything you really gotta give it a long time for fluid to settle down the dipstick tube. I always read when hot cuz the cold always seems inaccurate to me. I have struggled reading just like you too, but I read based on both edges ("sides" gets confusing) of the same side of the stick being coated. A lot of times one edge will be coated higher than the other but I don't take that high side as being accurate. Not sure what others do.
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Old May 18, 2023 | 01:04 PM
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Old May 18, 2023 | 01:05 PM
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Originally Posted by resharp001
I agree, that dipstick is difficult to read, not to mention when adding anything you really gotta give it a long time for fluid to settle down the dipstick tube. I always read when hot cuz the cold always seems inaccurate to me. I have struggled reading just like you too, but I read based on both edges ("sides" gets confusing) of the same side of the stick being coated. A lot of times one edge will be coated higher than the other but I don't take that high side as being accurate. Not sure what others do.
I seem to be a tad over, my jeep is raked a bit because i have metalcloak 2.5 inch springs, and a real light rear end. Should i take a little out, or do you think im fine? If i should take some out, how much, 1/4 a quart or less?
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Old May 18, 2023 | 01:21 PM
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The NAG1 has a float in the bottom of the shaft chamber, which blocks most of the fluid from coming in contact with the spinning gear stack. To either side of the shaft chamber, there is a void in the casting (the chamber is round, and the casting is square at the bottom. This void is open to the chamber on the side upstream of the shafts rotation. So any fluid that is flung off the stack gets funneled into the sump/pan. If the trans is overfilled (or very off angle, doing high G turns, etc), the fluid level can rise high enough to enter the chamber/bore. The float blocks most of it, and the rest gets tossed back into the funnel, and gets held there for the most part. So the trans tolerates overfilling to a certain degree, but it will start frothing out of the vent hole if more than a little overfilled.
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With how jeeps are used and that they can get really offcamber, is it better to be "lower" on fluid because of this? The damn jeep world man, i feel like i know a decent amount and nothing at all at the same time


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Old Jun 20, 2023 | 12:05 PM
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My 2009 JK unlimited X had the transmission rebuilt recently and I have a mishimoto transmission cooler on it. I checked my transmission fluid the other day when it was cold because I also replaced a leaky trans line after the rebuild and a lot spilled out and it read about half an inch above the hot fill line. Should I remove some?

Last edited by Smokinjoe37; Jun 20, 2023 at 12:07 PM. Reason: Typos
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Old Jun 21, 2023 | 02:04 PM
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Originally Posted by Smokinjoe37
My 2009 JK unlimited X had the transmission rebuilt recently and I have a mishimoto transmission cooler on it. I checked my transmission fluid the other day when it was cold because I also replaced a leaky trans line after the rebuild and a lot spilled out and it read about half an inch above the hot fill line. Should I remove some?
We have different trans, 5 speed mercedes, vs 4 speed chrylser. You should check it when its hot, sorry im no help
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Old Jun 21, 2023 | 02:10 PM
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Originally Posted by JeepLiam
We have different trans, 5 speed mercedes, vs 4 speed chrylser. You should check it when its hot, sorry im no help
Mine is 4 speed Chrysler baby
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